Nightmare: Historian finds out that another author was working on his topic just as both their books appear

It's the stuff of scholarly nightmares.

You spend years working on a book, toiling in archives, poring over sources, examining and re-examining data, only to discover that you're not alone. Someone else is working on more or less the same book.

It happened to Elisabeth Gitter. Ms. Gitter, a professor of English at the City University of New York's John Jay College of Criminal Justice, spent roughly a decade researching her book on Laura Bridgman. Bridgman was the most-famous deaf-blind girl in the United States pre-Helen Keller, but had been largely lost to history.

Ms. Gitter was going to single-handedly rescue Bridgman from obscurity. That was the plan, anyway. Then she got a phone call from her editor. Turns out, another scholar had also spent years working on a Bridgman book and, worse, that book was scheduled to come out at the same time as hers. "I was knocked off my feet," Ms. Gitter remembers.

The professor — perhaps naïvely, she says now — considered Bridgman her possession, and the idea that someone else was writing about her made Ms. Gitter feel like she'd been robbed. It was months before she recovered.

The other author, Ernest Freeberg, an associate professor of history at the University of Tennessee, was also initially distressed. "You think you're working on something that's going to be a big surprise to everyone," he says. "But it turns out to be a big surprise to everyone but one."...